Interband tunneling-based ULSI-compatible silicon devices

We discuss two classes of silicon devices based on interband tunneling. In the lateral interband tunneling transistor (LITT), an interband tunneling drain current I-D flows under reverse bias in the heavily doped source-drain pn junction in a thin Si channel on an SOI substrate. The tunneling I-D depends strongly on the peak electric field, which is controlled by the gate voltage V-G. The LITT has no inversion channel or minority carrier injection, promising very fast amplification; lack of inversion channel also means different scaling behavior compared to ordinary transistors. In the Si/SiGe multiemitter tunneling heterojunction bipolar transistor (MT-HBT), interband tunneling in a reverse-biased emitter-base junction supplies the controlling current. No base contact is needed, the device operates as an HBT with high gain, and the emitter contact symmetry provides enhanced logic (xor or ornand in a single device) with < 1 V logic levels and > 60 dB on/off ratio.